Attention alters the appearance of motion coherence

Abstract

Selective attention enhances visual information processing, as measured by behavioral performance and neural activity. However, little is known about its effects on subjective experience. Here, we investigated the effect of transient (exogenous) attention on the appearance of visual motion, using a psychophysical procedure that directly measures appearance and controls for response bias. Observers viewed pairs of moving dot patterns and reported the motion direction of the more coherent pattern. Directing attention (via a peripheral precue) to a stimulus location increased its perceived coherence level and improved performance on a direction discrimination task. In a control experiment, we ruled out response bias by lengthening the time interval between the cue and the stimuli, so that the effect of transient attention could no longer be exerted. Our results are consistent with those of neurophysiological studies showing that attention modulates motion processing and provide evidence of a subjective perceptual correlate of attention, with a concomitant effect on performance.

Transient covert attention does alter appearance: A reply to Schneider (2006)

“…Thus, a long interval between the cue and target should eliminate any effect that it may have on perception, and any residual difference between the neutral and peripheral cues would be attributed to a cue bias. When the cue preceded the display by 500 msec, there were no systematic differences between the neutral and peripheral conditions in the appearance of contrast (Carrasco, Ling, & Read, 2004) and of motion coherence (Liu et al, 2006). Thus, when transient attention was no longer active, the appearance of the stimulus was not altered.…”

“…Whereas in many studies investigating the effect of attention on performance in visual tasks a black peripheral cue has been used (Carrasco, Ling, & Read, 2004;Carrasco et al, 2000;Hsieh et al, 2006;Lu & Dosher, 1998, a green cue has shown to affect texture segmentation (Yeshurun & Carrasco, 1998 and to improve acuity (Yeshurun & Carrasco, 1999). Using a black cue, as in the apparent-contrast article referred to (Carrasco, Ling, & Read, 2004), transient attention has been shown to increase perceived spatial frequency and gap size (Gobell & Carrasco, 2005), as well as perceived motion coherence (Liu et al, 2006) and perceived speed (Turatto et al, 2007). Using a white precue, we have also reported that transient attention increases perceived flicker (Montagna & Carrasco, 2006) and perceived color saturation, but not hue .…”

“…We implemented a paradigm that allowed us to measure perceived contrast without asking observers to do so directly. Moreover, because our observers performed an orientation discrimination task contingent upon appearance, we had an objective index indicating that the observers were performing the task and that the cue was effective (Anton-Erxleben et al, 2007;Carrasco, Ling, & Read, 2004;Liu et al, 2006). Many have commented on the strengths of this simple paradigm (Luck, 2004;Treue, 2004).…”

“…Using this paradigm, it has been reported that attention alters our subjective impression of many dimensions: contrast appearance (Carrasco, Ling, & Read, 2004;Hsieh et al, 2005), spatial frequency and gap size (Gobell & Carrasco, 2005), flicker rate (Montagna & Carrasco, 2006), motion coherence (Liu et al, 2006), size of a motion stimulus (Anton-Erxleben, Henrich, & Treue, 2007), perceived speed (Turatto et al, 2007), and color saturation (but not hue; . For a review, see Carrasco (2007).…”

Cross-modal cueing in audiovisual spatial attention

“…Such cueing effects are typically interpreted as attention effects: It is assumed that spatial attention facilitates the perception of stimuli presented at the cued location. While some studies focused on response speed (Posner, 1980;Posner, Snyder & Davidson, 1980;Jonides, 1981), other studies used perceptual decision tasks to test response accuracy (Bashinski & Bacharach, 1980;Dosher & Lu, 2000;Carrasco, Ling & Read, 2004;Liu, Fuller & Carrasco, 2006;Fairhall & Macaluso, 2009).…”